Ballpoint pen



FIG. 1 is a front elevation view of a ballpoint pen according to my new design;

FIG. 2 is a bottom view of the ballpoint pen of FIG. 1;

FIG. 3 is a top view of the ballpoint pen of FIG. 1;

FIG. 4 is a right side view of the ballpoint pen of FIG. 1, the left side view being a mirror image thereof; and,

FIG. 5 is a rear view of the ballpoint pen of FIG. 1. 

The ornamental design for a ballpoint pen, as shown and described. 